The satellite link that keeps watch on your children

Its vivid colour is clearly designed to appeal to youngsters. But this watch is really aimed at their parents.

For its key selling point is a satellite positioning system that locates the wearer to within ten feet.

The makers claim the GPS tracking device will offer anxious parents peace of mind and allow children the independence to go out to play on their own.

The num8 watch costs £149.99 and can be securely fastened to a child's wrist, triggering an alert if forcibly removed

But critics have said the 'tagging' is a step too far in the climate of paranoia over child safety.

The num8 watch, pictured above, costs £149.99 and can be securely fastened to a child's wrist, triggering an alert if forcibly removed.

Parents will be able to see their child's location on Google maps by texting 'wru' to a special number, or clicking 'where r you' on the secure website linked to the device. The street address and postcode will be displayed.

Safe zones can also be set up in which children can play. An alert will be sent to the parents if the child strays out of that area.

Steve Salmon, of makers Lok8u, said: 'Losing your child, if only for a brief moment, leads to a state of panic and makes parents feel powerless. The overriding aim of num8 is to give children their freedom and parents peace of mind.'

But Dr Michele Elliott, director of children's charity Kidscape, said: 'Is the world really that unsafe that parents need to track their children electronically? I don't think so.'